In the aftermath of high-altitude nuclear tests conducted by the United States, e.g., in the Starfish Prime test performed on Jul. 9, 1962, researchers noticed the formation of a nuclear fireball that disrupted all sorts of communications including both one-way and two-way communications. This disruption is referred to as a fireball blackout, also known as nuclear blackout or radar blackout, because the nuclear fireball contains highly ionized plasma spread over large areas, e.g., hundreds of miles, that strongly refract radio waves to render communication systems inoperable.
This blackout effect may be particularly concerning for military systems such as anti-ballistic missile (ABM) systems that rely on radar technology. In typical operation, an ABM system implements a radar that transmits signals via radio waves. Upon encountering an object, the radio waves are scattered by the object and reflected to the radar system as echo signals that are analyzed by the radar to detect and identify the object as, e.g., an incoming missile. In a nuclear-scintillated environment, the plasma in the nuclear fireball causes radar signals to be so heavily refracted that radar systems cannot track and identify objects. Even as the plasma cloud cools and dissipates over a period of minutes, the radar signals may still be so attenuated and distorted as to render ABM systems inoperable. Therefore, in this blackout period, the efficacy of ABM systems is reduced as ABM systems cannot reliably detect, track and identify incoming missiles.